With roads and bridges destroyed, and some rail services in the country shut down, people trapped in the area have received aid from a surprising ally.

Video has emerged from the region showing Asian elephants rescuing those trapped by dangerous flood waters. On Monday, hundreds of tourists were rescued from a popular resort in Nepal and transported 11 miles to safety. Most recently, a man was spotted riding an elephant through the streets of Sauraha, a town in central Nepal near the northeastern Indian border.

So who are these rescue elephants?

Many are domesticated elephants that were caught as calves. Elephants breed poorly in captivity, meaning many of the elephants used by people are caught and trained to work and live alongside them.

In addition to being highly intelligent, elephants are capable of a remarkable amount of empathy, says Joyce Poole, an elephant expert and co-founder of Elephant Voices.

During a natural disaster, elephants would likely be able to discern that a dangerous situation has struck.

"They would understand that a person is in trouble and that it's a dangerous situation," says Poole, who is also a National Geographic explorer. Elephants have good senses of smell and have been known to alert rescuers to people trapped in a building.

Elephants have not only been observed saving young calves from drowning, they've also been filmed attempting to save people they see at risk of drowning. Using elephants as a form of transportation, however, is nothing new. In this region, people have been using elephants for thousands of years.

According to a UN report, seals from the Indus Valley civilization place domestic elephants in the region as far back as 2500 B.C. Since then, elephants have been used for a number of purposes, from being ridden into war, to irrigation, to logging. Today, they are more frequently domesticated to be ridden as tourist attractions. The park at which Reuters reports hundreds were rescued by elephants is frequently visited by people looking to ride elephants or see rhinos.

Their cultural significance means that many are kept in captivity—an estimated 15,000, a third of the population, are captive.

Despite the empathy captive elephants show to people, young elephants must still undergo a long process to make them suitable for training.

And the training can often be brutal.

Elephants are highly social, and matriarchal units can form intense bonds. Poole explained that to train elephants, handlers must "break their spirit."

"It involves tying them up, not giving them food or water, stretching them out, and prodding them with bull hooks."